福州大学土木工程学院
TU528.572
国家自然科学基金项目（52278490），福建省自然科学基金项目（2022Y3001, 2023J01343, 2023-K-104, 2023-K-109）
College of Civil Engineering, Fuzhou University
冲击荷载的随机性严重影响了混凝土结构的安全，在混凝土中加入玄武岩纤维(BF)或聚乙烯纤维(PEF)可改善混凝土的抗冲击性能。在准静态试验的基础上，使用分离式霍普金森压杆(SHPB)装置研究了素混凝土(PC)、玄武岩纤维混凝土(BFRC)和聚乙烯纤维混凝土(PEFRC)在不同应变率下的动态力学性能。分析了三种混凝土的静态抗压强度、静态劈裂抗拉强度、动态抗压强度和动态压缩韧性的变化规律。结果表明：单独加入BF或PEF明显提升了混凝土的静态抗压强度和劈裂抗拉强度，BF掺量0.10%时BFRC表现出最佳抗压强度和劈裂抗拉强度，PEFRC的最佳PEF掺量则为0.20%。在74、106和145 s-1三种应变率下，BF和PEF掺量均为0.20%时混凝土动态抗压强度提升效果最佳，PEF掺量0.15%时PEFRC表现出最佳动态压缩韧性。基于朱-王-唐（ZWT）本构模型所建立的动态损伤本构模型与试验曲线吻合程度良好，说明其可较好地反映纤维混凝土(FRC)在冲击荷载下的行为特性。
The unpredictability of impact loads significantly affects the safety of concrete structures. Incorporating basalt fiber (BF) and polyethylene fiber (PEF) into concrete enhances its impact resistance. Based on quasi-static tests, the dynamic mechanical properties of plain concrete (PC), basalt fiber-reinforced concrete (BFRC), and polyethylene fiber-reinforced concrete (PEFRC) at different strain rates were investigated using the split-Hopkinson pressure bar (SHPB). The variations in static compressive strength, splitting tensile strength, dynamic compressive strength, and compressive toughness of the three types of concrete were analyzed. The results indicated that the addition of BF and PEF significantly improves the static compressive and splitting tensile strengths of concrete. At a BF volume fraction of 0.10%, BFRC exhibited the highest static compressive and splitting tensile strengths, while the optimal PEF volume fraction for PEFRC was 0.20%. In terms of SHPB tests, under strain rates of 74 s-1, 106 s-1, and 145 s-1, the dynamic compressive strength of concrete was optimized at a BF and PEF volume fraction of 0.20%, while PEFRC exhibited the best dynamic compression toughness at a PEF volume fraction of 0.15%. The dynamic damage constitutive model for BFRC and PEFRC developed from the Zhu-Wang-Tang (ZWT) constitutive model aligned well with the test results, indicating that the models more accurately reflect the dynamic behavior of fiber-reinforced concrete (FRC) under impact.
